The instant invention relates to protective eyewear, and more particularly to a protective eyeglass assembly including a unitary, decentered lens piece which can be readily assembled and disassembled with a frame or a pair of temple bars for quick and efficient interchange of the frame and/or replacement of the lens piece, and which reduces optical distortion.
The importance of wearing safety or protective glasses in many industrial environments is widely recognized, and as a result, a variety of different types and styles of protective eyeglasses have been heretofore available. While the currently existing protective eyeglasses are adequate for their intended purpose, there is nevertheless a continuing need for improved versions of protective eyeglasses. In this regard, protective eyeglasses which mimic current designer frame styles and which offer versatility to change frame colors or styles, and to replace lens pieces are believed to be highly desirable in the market.
An example of one type of protective eyeglass assembly can be found in applicant's co-pending patent application, Ser. No. 08/635,204, entitled PROTECTIVE EYEGLASS ASSEMBLY. This patent application discloses a protective eyeglass assembly comprising a frame, and a lens piece which is adapted to be detachably secured to the frame so that a user can interchange the frame for another frame of the same type, but of a different color or appearance, and/or replace the lens piece if the lens piece becomes damaged. The frame comprises left and right lens frame portions, left and right lens receiving apertures respectively formed in the left and right lens frame portions, a bridge portion connecting the left and right lens frame portions, and left and right temple bars extending rearwardly from the left and right lens frame portions. Preferably, the temple bars are angularly adjustable with respect to the left and right lens frame portions, and are also telescopically adjustable in length.
The lens piece is preferably integrally molded from a durable, transparent, plastic material and includes left and right lens panels, a central bridge portion connecting the left and right lens panels, left and right side shields extending rearwardly from left and right side extremities of the left and right lens panels, and left and right upper shields extending between left and right upper extremity portions of the left and right lens panels, and the left and right side shields, respectively. The left and right lens panels, left and right side shields, and left and right upper shields each have a uniform thickness.
The lens piece is received in assembled relation with the frame with the left and right lens panels aligned in registry with the left and right lens frame portions. The lens piece and the frame are secured in assembled relation by means of interengaging formations on the frame and lens piece. More specifically, the left and right temple bars each include an inwardly extending, horizontally disposed T-shaped pin, while the left and right side shields of the lens piece include a complementary vertically disposed slot for receiving their respective pins. The central bridge portion of the lens piece further includes a detent, while the bridge portion of the frame includes a small recess for receiving the detent. To assemble the frame and lens piece, the temple bars of the frame are bent outwardly to insert the pins into the slots in the side shields of the lens piece. In this regard, the lens piece is originally positioned with the lens panels facing downwardly so that the slots in the side shields are disposed horizontally and aligned with the pins, and then the lens piece is rotated forwardly and upwardly with respect to the frame to engage the lens piece detent with the recess in the bridge portion of the frame. The pins along with the detent cooperate to maintain the lens piece in assembled relation with the frame.
It has been found that the protective eyeglass assembly as disclosed in the aforementioned patent application has significant marketing advantages over existing protective eyeglasses. Specifically, because the lens piece is removable from the frame, the frame can be interchanged with another frame of a different color or appearance by simply disassembling the lens piece from the original frame and assembling it with a new frame. Furthermore, the particular design of the frame and lens piece is intended to minimize the visibility of the lens piece, and thereby create the perception of a conventional pair of designer glasses rather than a bulky pair of protective goggles. The provision of designer style protective eyewear makes it more fashionable to wear the protective eyewear, and thus increases the number of people who will actually wear protective eyewear. Still further, because of the unitized construction of the lens piece and the manner in which it is adapted for assembly with the frame, the lens piece is able to provide highly effective eye protection. Even further still, the overall construction of the frame and lens piece enables the protective eyeglasses of the subject invention to be comfortably and effectively worn by a user for a prolonged period of time.
Although perfectly suitable for its intended purpose, the eyeglass assembly disclosed in the aforementioned patent application does suffer from the disadvantage of distorting the wearer's vision. Specifically, the uniform thickness of the left and right lens panels incur a nominal amount of prismatic distortion. The present invention overcomes this disadvantage by providing a unitary, decentered lens piece which is tapered to significantly reduce such distortion.